A severe weather warning of heavy rain remains in place for Bracknell, Reading and Wokingham on Saturday but the overall forecast seems to be improving.

The Met Office yellow warning is still in place between 4am and 1pm but the probability of heavy rain has dropped to 40 per cent during the day. Earlier in the week the agency were predicting a probability of 60 per cent.

The agency say thundery downpours are expected during Saturday and that people should be aware of the potential for localised flooding due to the intensity of these storms.

Experts at the University of Reading are warning that flash floods could be on the way for some parts of the country because the ground is still wet from heavy rain during the winter months.

Flooding expert Dr Hannah Cloke said: “We could see flash floods in some parts of Britain if rainfall this weekend is as intense as has been predicted. The problem is likely to be exacerbated in areas where the ground is still wet from the winter floods, particularly in catchments with high groundwater levels and where rivers are still high following Britain’s wettest winter ever.

“Urban areas and small, steep catchments are likely to be vulnerable, especially those with little soil to absorb the water. Some towns and major roads could be quickly swamped as drainage systems become overwhelmed.

“But when it rains very heavily, almost anywhere could be at risk. Extremely intense bursts of rain can mean that the soil is simply unable to soak up the water fast enough, so excess water runs off and causes floods in all sorts of unexpected places.”

“A low pressure system sitting off the west coast of Ireland pulls warm, humid air north from France. The front from the system passes the UK adding extra possible uplift for storms. This is the perfect recipe for an explosive thunderstorm.

“It is likely that there will be intense thunderstorms with very heavy rain, providing the potential for flash flooding."

Meteorologist Dr Roger Brugge said: “The start of 2014 has been the wettest first five months of any year on record. Following the wet winter, spring (March-May) has also seen more rain than normal this year. At the University of Reading’s observatory 194 mm of rain fell – about 50 per cent more than normal – making it the wettest spring here for six years.

“So far this year the rainfall total at the University tallies 462 mm, some 25 mm more than in any other January-May period in the past century in Reading. The same five months have also been much milder than usual – although 2007 and 2011 were even warmer.”